Liquid acidic detergent iodine concentrates



United States Patent ()fifice 3,220,951 Patented Nov. 30, 1965 3,220,951 LIQUID ACIDIC DETERGENT IODINE CON CENTRATES Abraham Cantor, Elkins Park, Pa., and Otto E. Neracher,

Mount Vernon, and Murray W. Winicov, Flushing,

N.Y., assignors to West Laboratories, Inc., Long Island City, N.Y., a corporation of New York No Drawing. Filed Mar. 30, 1962, Ser. No. 183,713

4 Claims. (Cl. 252-106) This invention relates to improved detergent iodine compositions having germicidal properties, and to methods for preparing the same. More particularly, the invention relates to improved high acid detergent iodine compositions and methods for preparing the same, characterized in that products in commercially practical concentrate form, having low viscosity and capable of dilution with water in proportions to form stable consumer products and germicidal use dilutions, can be provided by forming a complex of iodine with a water soluble nonionic surface active agent in the presence of hydroxyacetic acid as the only or primary acidifying agent.

In the detergent iodine field, and particularly in connection with environmental sanitation uses of detergent iodine products, it is frequently desirable to incorporate phosphoric acid in each product in substantial concentration as a protective agent for the iodine, prolonging its effectiveness in the presence of organic soil, water hardness, and the like, which tend to dissipate the iodine activity. Such use of phosphoric acid is the subject matter of Scheib et al. Patent No. 2,977,315.

While this use of phosphoric acid is practical in the direct preparation of consumer products, which generally contain less than about 2% available iodine, the preparation of such products requires substantial specialized equipment which is not available to many of the smaller formulators of germicidal detergent iodine products. For such smaller formulators, there is a practical need for procurement of pre-formulated detergent iodine compositions in concentrate form, so that consumer products can be produced therefrom by simple dilution, without necessarily blending inof other formulating components. At this point, however, the practicality of phosphoric acid becomes questionable, since as the amount of iodine in a detergent iodine concentrate is increased, there is a rapid increase in viscosity as phosphoric acid is combined therewith. While the increase in viscosity does not impair the germicidal properties, it makes the concentrate difiicult to handle both during preparation and in use when preparing dilutions or reformulations thereof as consumer products. It has been found, for example, that a practical upper limit for viscosity (expressed in centipoises as measured by the Brookfield viscometer) for liquid which can be readily handled with normal mixing equipment is about 1000 centipoises. Attempts to use normal mixing equipment with materials having viscosities higher than about 1000 centipoises result either in malfunctioning of the equipment, or improper mixing; and special equipment to handle mixing of high viscosity liquids becomes prohibitive in cost.

The problems of high viscosity in detergent iodine concentrates are not confined to those containing phosphoric acid, but arise with a number of detergents which are practical for use in consumer products, but which are by themselves highly viscous. One approach to this problem,

as taught in Brost US. Patent No. 2,989,434 is to combine the desirable detergent with a compatible, less viscous, surface active agent which by itself would be water insoluble, but which, in combination with the preferred detergent becomes water miscible while substantially reduc-' ing the viscosity of iodine concentrates prepared therefrom. This solves the immediate problem of enabling the preparation of fluid concentrates containing as much as about 20% iodine, but introduces new problems in that such concentrates cannot be simply diluted to prepare consumer products. They must be reformulated at the time of dilution to include additional amounts of a preferred detergent to oflFset the poor detergency of the insoluble surface active agent contained in the concentrate. The need for such reformulating makes such a concentrate undesirable to a distributor of environmental sanitation products as compared with concentrates which can be simply diluted with the proper amount of Water to prepare a consumer product.

It has now been discovered, in accordance with the present invention that the viscosity problem in preparing acidic detergent iodine concentrates can be overcome by employing as the only acid, or the primary acid in such concentrate, hydroxyacetic acid. This organic acid provides a type of protection of the iodine against theeffect of organic soil, and the like, at use dilution comparable with the protection afforded by phosphoric acid, although its substantially higher cost makes it less attractive than phosphoric acid in the direct preparation of consumer products. It has been found, however, that hydroxyacetic acid has a surprising fluidizing elfect on normally viscous detergent iodine concentrates. In fact, detergent iodine concentrates containing an amount (x) of commercial hydroxyacetic acid are generally less viscous than similar concentrates in which said amount (x) of hydroxyacetic acid is replaced with Water.

Furthermore, it has been found that the fluidizing effect of the hydroxyacetic acid is so strong that it will under certain, and commercially practical conditions counteract the tendency of phosphoric acid to increase viscosity of the concentrates. In general, it has been found that if hydroxyacetic acid is present in amounts greater than about one-half the detergent-iodine content, concentrates having satisfactory viscosity, i.e., below about 1000 centipoises, can be obtained with added amounts of phosphoric acid up to an amount approximately equivalent to the hydroxyacetic acid content. In addition, of course, the amount of phosphoric acid to be included in conjunction with hydroxyacetic acid may be varied to meet the physical properties desired in a particular product. In some situations where maximum fluidity is desired in a concentrate, the amount of phosphoric acid included may be substantially less than an amount equivalent to the hydroxyacetic acid. On the other hand, if a more viscous concentrate is considered satisfactory, it may be possible to include phosphoric acid in an amount somewhat greater than an amount equivalent to the hydroxyacetic acid, and still maintain in the concentrate a viscosity below about 1000 centipoises, at 27 C.

The ability to thus regulate the viscosity of an acidic detergentiodine concentrate by varying the relative amounts of hydroxyacetic and phosphoric acids, has very real and practical advantages in the preparation of concentrates which can be diluted with water to provide consumer products. The detergents to be used can be seand iodine complexing capacities and withlittle regard to viscosity of the detergent per se. Iodine which may be added as elemental iodine, or more suitably as an aqueous solution of iodine and HI as disclosed in United States Patent No. 3,028,299 issuing April 3, 1962, in which latter event the HI added with the iodine prevents loss of iodine by interreaction with the detergent, and a stable iodine complex is directly obtained with substantially all of the iodine added being titratable as available iodine.

The total amount of acid tov be included in the concentrate may be varied considerably, depending upon the end use of consumer products to be prepared from the concentrate. For ordinary environmental sanitation purposes, the ratio of about 4:1 acid to available iodine will provide concentrate in which normal use dilutions, i.e., those containing about 5 to 25 -p.p.m. of available iodine will have a pH below about 4, assuming that the water used in preparing the use dilutions is not excessively alkaline. For the preparation of special type end use products, as for example those intended for use in the dairy industry and restaurant and food handling industries Where high concentrations of organic soil. are encountered, the ratio of acid to available iodine in the concentrate is advantageously increased to :1, :1, or even higher. Throughout the practical range in variation of acid content, however, it is to be understood that the fluidizing effect of hydroxyacetic acid can be relied upon to permit substantial inclusion of phosphoric acid in the concentrate in the manner above described. In

general, the higher the ratio of total acid to available iodine, the higher can be the proportion of phosphoric acid to hydroxyacetic acid while still maintaining in the concentrate a viscosity below about 1000 centipoises.

The following example will serve to provide a better understanding of the present invention and to show how typical commercially p ractical acidic detergent-iodine concentrate can be prepared using as the acid hydroxyacetic acid and mixtures of hydroxyacetic .and phosphoric acids, but not when using phosphoric acid alone. It is to be understood, however, that this example is given by way of illustration and not of limitation.

Example A number of detergent-iodine and acidified detergent iodine concentrates were prepared having differing compositions as indicated in the following table. The procedures employed involved adding with stirring to a Weighed amount of deter-gent, a weighed amount of iodine solution which is a 57% w./ W. solution of iodine in aqueous hydriodic acid containing 24% HI, and continuing stirring until homogeneous. For acidified concentrates, the designated proportion by weight and-type of acid, or acid mixture, was then added with stirring until homogeneous. Each of the concentrates prepared was tested for viscosity, expressed in centipoises, as measured by the Brookfield Viscometer, at 27 C. i

In preparing these concentrates, three diiferent detergents were employed; detergent being a nonyl phenol ethylene oxide condensate containing 10-11 mols of ethylene oxide per mol of nonyl phenol (Igepal CO-710), detergent B being a condensate of polypropylene oxide and ethylene oxide wherein the polypropylene oxide group has a molecular weight within the range of 1501 to 1800 and the condensate contains 20 to 30 percent of ethylene oxide (Pluronic 1,62), and detergent C being a condensate similar to detergent B, but containing 50 to 60% ethylene oxide (Pluronic P-65).

In the following tabulation Drepresents parts by weight of detergent; I represents parts by Weight of aqueous HI/I solution containing 24% HI and 57% iodine; X represents the additive water or acid; H represents commercial 70% aqueous hydroxyacetic acid, P represents 70% aqueous phosphoric acid; H-l-P represents equal parts by weight of H and P; and

' P-( represents commercial -85 phosphoric:

,The viscosity values in the foregoing tabulation indicate very clearly the fluidizing effect of hydroxyacetic acid on detergent iodine concentrates, and the extent to which this fluidizing effect persists in the presence of phosphoric acid. The values in connection with "item d in the tabulation indicate a somewhat less than minimal ratio of hydroxyacetic acid to the. combined detergent and iodine tor fluidizing the product with an amount of phosphoric acid which is equivalent to the hydroxyacetic acid.

The method of introduction ofhavailable iodine has, little eifect on the final viscosity properties of the concentrate. For purpose of illustration,-the concentrates embraced in the foregoing tabulation were prepared supplying' the available iodine in the form of aqueousl-II/I solution. Other iodides, such as the alkali metal iodides can be substituted for the HI in providingthe starting aqueous iodine solution. In addition, it is to'be understood that the older technique ofdissolving elemental iodine directly in the detergent can be employed without substantially modifying the viscosity characteristics of the various concentrates. The latter method of formulation, however, has the disadvantage of producing a concentrate in which substantial amounts of the initially available iodine will. be consumed by interreaction with the detergent upon standing and/ or heating.

The present invention is applicable to acidic-iodine con centrates generally, which contain water soluble nonionic surface active agents having detergent properties that are themselves'ei'lective iodine carrier's. By way of illustra: tion, there is presented in the following table comparative data with respect to several quite-different water soluble nonionic surface active agents. In determining the viscosity values in the tabulation, concentrates containing detergent iodine and either hydroxyacetic or phosphoric acid were prepared in accordance with the procedure pre: viously described, with the relative proportions of detergent iodine and acid being 1022114 as indicated for items f and h in Table I. The several detergents employed are identified as follows:

(l) The I'gepal CO-7l0 identified as Table I.

(2) Tridecyl alcohol condensed with 12 moles of ethylene oxide'(SurfonicTD-120).

(3) Alkoxypolypropoxypolyethoxyethanol (Te'rgitol The tabulation shows a comparison in the viscosities when the several concentrates are acidified with hydroxyacetic acid (H) and with phosphoric acid (P).

detergent A in TABLE II Viscosity in Centipoises Detergent H l P Commercially practical concentrates in accordance with the present invention may contain about 3 to and preferably about 4 to 8% by weight of iodine (meaning available or titratable iodine), and the ratio of nonionic detergent to iodine may range from 4/1 to 20/1, and preferably about 5/1 to 10/1. The remainder of the concentrate is essentially made up of hydroxyacetic acid alone, or in combinaiton with phosphoric acid, with the relative proportion of phosphoric acid permissible being limited as herein described, to an amount which will not carry the viscosity of the concentrate higher than about 1000 centipoises. In general, the ratio of hydroxyacetic acid to iodine should be in excess of about 2 to 1 with a preferred range being about 4 to 10 times the amount of available iodine. In instances when no phosphoric acid is employed, however, it is preferable to include an amount of hydroxyacetic acid in excess of about 5 times the amount of available iodine.

In all the concentrates shown in the foregoing tabulations, the combined weight of available iodine, detergent and acid is equivalent to about 60% to 85% by weight of the concentrate; and it is to be understood that the term concentrate as used herein means a composition in which the active components thus constitute in excess of about 60% by weight of the composition.

Various changes and modifications in the acidic detergent iodine concentrates herein disclosed will occur to those skilled in the art, and to the extent that such changes and modifications are embraced by the appended claims, it is to be understood that they constitute part of the invention.

We claim:

1. A liquid acidic detergent iodine concentrate consisting essentially of iodine, a water soluble ethoxylated nonionic surface active agent having detergent properties which is itself an effective iodine carrier, an acid selected from the group consisting of hydroxyacetic acid and mixtures of hydroxyacetic acid with up to an approximately equivalent amount by weight of phosphoric acid and water, wherein the amount of available iodine is about 3 to 10% by weight of said concentrate, the proportion of detergent to iodine is within the range of about 4/1 to 20/ 1, the amount of said acid provides a ratio of hydroxyacetic acid to iodine in excess of about 2 to 1, and sufficient to impart to said concentrate a viscosity below about 1000 centipoises, at 27 C., and the components of said concentrate exclusive of water constituting about to by weight of said concentrate.

2. A liquid acidic detergent iodine concentrate as defined in claim 1 wherein the amount of available iodine is within the range of about 4 to 8% by weight of said concentrate, the proportion of detergent to iodine is within the range 5/1 to 10/ 1, and the amount of acid provides a ratio of hydroxyacetic acid to iodine in the range of about 4/1 to 10/1.

3. A liquid acidic detergent iodine concentrate consisting essentially of iodine, a water soluble ethoxylated nonionic surface active agent having detergent properties which is itself an effective iodine carrier, hydroxyaceitc acid and water, wherein the amount of available iodine is about 3 to 10% by weight of said concentrate, the proportion of detergent to iodine is within the range of about 4/1 to 20/1, the proportion of hydroxyacetic acid to iodine is in excess of about 5 to l, and suflicient to impart of said concentrate a viscosity below about 1000 centipoises, at 27 C., and the components of said concentrate exclusive of water constituting aobut 60 to 85% by weight of said concentrate.

4. A liquid acidic detergent iodine concentrate as defined in claim 3 wherein the amount of available iodine is within the range of about 4 to 8% by weight of said concentrate, and the proportion of detergent to iodine is within the range 5/1 to 10/1.

References Cited by the Examiner UNITED STATES PATENTS 2,977,278 3/1961 Shelanski et al 167-17 2,977,315 3/1961 Scheib et a1 252106 3,028,299 4/1962 Winicov 16717 3,029,183 4/1962 Winicov 16717 3,150,096 9/1964 Schmidt et al. 252106 OTHER REFERENCES Chemical and Engineering News, Apr. 15, 1957, p. 80.

JULIUS GREENWALD, Primary Examiner. ALBERT T. MEYERS, Examiner. 

1. A LIQUID ACIDIC DETERGENT IODINE CONCENTRATE CONSISTING ESSENTIALLY OF IODINE, A WATER SOLUBLE ETHOXYLATED NONIONIC SURFACE ACTIVE AGENT HAVING DETERGENT PROPERTIES WHICH IS ITSELF AN EFFECTIVE IODINE CARRIER, AN ACID SELECTED FROM THE GROUP CONSISTING OF HYDROXYACETIC ACID AND MIXTURES OF HYDROXYACETIC ACID WITH UP TO AN APPROXIMATELY EQUIVALENT AMOUNT BY WEIGHT OF PHOSPHORIC ACID AND WATER, WHEREIN THE AMOUNT OF AVAILABLE IODINE IS ABOUT 3 TO 10% BY WEIGHT OF SAID CONCENTRATE, THE PROPORTION OF DETERGENT TO IODINE IS WITHIN THE RANGE OF ABOUT 4/1 TO 20/1, THE AMOUNT OF SAID ACID PROVIDES A RATIO OF HYDROXYACETIC ACID TO IODINE IN EXCESS OF ABOUT 2 TO 1, AND SUFFICIENT TO IMPART TO SAID CONCENTRATE A VISCOSITY BELOW ABOUT 1000 CENTIPOISES, AT 27*C., AND THE COMPONENTS OF SAID CONCENTRATE EXCLUSIVE OF WATER CONSTITUTING ABOUT 60 TO 85% BY WEIGHT OF SAID CONCENTRATE. 